The selenium state of healthy children

The selenium concentration of serum is age-dependent. The median value at birth ( \(\tilde x\) =50×10⁻⁹g/ml) amounts to half of the median value of adults ( \(\tilde x\) =102×10⁻⁹g/ml). After a decrease in early infancy to \(\tilde x\) =34×10⁻⁹g/ml it steadily increases to \(\tilde x\) =58×10⁻⁹g/ml in the second half of the first year, to \(\tilde x\) =82×10⁻⁹g/ml in 1–5 year old children, and to \(\tilde x\) =92×10⁻⁹g/ml in school children. The activities of the selenium containing enzyme glutathione peroxidase of erythrocytes are also reduced in early infancy (x=7.2±0.36 U₃₇/g Hb), whereas the enzyme activities of cord blood erythrocytes (x=8.72±0.76 U₃₇/g Hb) are in the same range as those of older children or adults. The selenium content of some commercially available milk formulas for infants are lower than those of human and cow's milk.